Born in New York on February 11, 1931. Merchant graduated with a degree in journalism from Oklahoma University.

After two years in the Army, where he served as sportswriter for Stars and Stripes, he was discharged in 1953 and became sports editor for the Wilmington News. A brief turn at the Associated Press followed before he was named sports editor of the Philadelphia Daily News where he wrote a column five days a week. In 1965 he relocated to New York to be a columnist for the New York Post. He left the Post in 1975 and worked as a reporter and commentator for NBC and wrote a general-interest column for the Los Angeles Herald-Examiner.

In 1978 he joined HBO Sports as an expert analyst for their boxing telecasts and has been at ringside ever since. His first fight on HBO was James Scott vs. Eddie Gregory at Rahway State Prison. His primary role at HBO is pre- and post-fight analysis, as well as post-fight interviews.

Merchant was awarded the 1985 Sam Taub Memorial Award for Excellence in Boxing Broadcast Journalism by the BWAA. An accomplished author, he has penned three books and also served as writer for the HBO documentary series Legendary Nights.